Engine starting apparatus



J. ELANTON IDIS ENGINE smiwme APPARATUS 'Sept. 20, .1949.

Filed July 2, 1948 3 Sheets-Sheet l N HVVENTDR A N 398 Pm p 1949. A J. E. ANTQNIDIS 7 2,482,534 I ENGINE STARTING APPARATUS s Sheets-'-Sne t 2 Filed July 2, 1948 Sept, 20, 1949;

J. E. ANTONIDIS ENGINE STARTING APPARATUS 3 Sheets-Sheet 3 Filed July 2, 1948 Patented Sept. 20, 1949 EN GINE STARTING APPARATUS John E. Antonidis, Anderson, Ind., assignor to v I Y General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application July 2,1948, Serial No. 36,636

This invention relates I to electrical engine starting apparatus of the type which includes a pinion connecting with the shaft ofthe starting motor and movable therealonginto mesh with the engine flywheel gear and which includesan electromagnet which operates. through a spring to shift the pinion and .whichcloses the starting motor switch, the spring yieldingin case of abutment of the pinion with the engine gear to permit closing of the switch by-the electromagnet so that the motor can operate to release the abutment whereupon the spring is released quickly to move the pinion into mesh withthe engine gear. Electromagnets or solenoids for this purpose are disclosed in Dyer Patent 2,287,791 and Claytor Patent 2,318,672.- 7

An object of the present invention is to reduce the cost of the solenoid. 'I havefound that it is possible to usea solenoid ofsmaller dimensions and requiring less magnet wire by a construction which provides in case the pinio n abuts the engine gear, that the forcethen opposing further movement of the solenoid armature is applied axially of the arr'nature. and not obliquely thereby minimizing the force required to overcome friction and making possiblelthe use-f substantially all of the magnetic force tojstart deflection of the spring. As the spring is deflected by movement of the armature toward a fixed core, the opposing force becomes slightly oblique and the friction between thearmature and its guide -inthe relation between the lflywheel gear and the flywheel housing to which the starting apparatus is attached. This object isv accomplished by providing for the attachment of the solenoid housing to the motor field frame by means which permits adjustment of theformer relative to the,

latter.

A further object is to prevent the entrance of dirt and moisture. into the guide bearing provided by the solenoid housing for supporting the solenoid armature for axial movement. This is accomplished by the use of .a flexible rubber boot connected with the housing and armature and enclosing the portion of the armature exterior to the housing, said boot permittingthe adjustment mentioned in the. preceding paragraph.

Further objects and advantages of the present *3 Claims. (o1. 74-1) invention will be apparent from thefollowing description, reference being had to the accompanying drawings, wherein a preferred embodiment'of the present invention is clearly shown.

In the drawings:

Fig. 1 is a side view, partly in longitudinal section, of engine starting apparatus embodying the present invention. 7 r I Fig. 1A is a fragmentary view in the direction of arrow IA of Fig. 1.

Fig. 2 is'a longitudinal, solenoid.

Fig. 2A is a sectional view on line-2A2A of Fig. 2.

Fig. 3 is a view in the direction of arrow 3 of Fig. 2.

' Fig. 4 is a sectional view on line 4-4 of Fig. 3. Fig. 5 is a sectional view on line 5-5 of Fig. 2. Fig. 5A is a sectional viewv on line 5A-5A of Fig.5.

Fig. 6 is a view in the direction of arrow 6 of Fig. 2. i Y Fig. 7 is a fragmentary, sectional view of solenoid and a boot for protecting the solenoid armature.

Fig. 8 is a view similar to Fig. 7, showing the boot compressed.

Fig. 9 is an end view of the boot.

Fig. 10 is anend view of shell 66 and plate 60 modified to retain the boot.- 7

Fig. 11 is a view in the direetion of arrow ll of Fig. '7, lever M being omitted. Fig. 12 is a longitudinahsection'al view of link 41 Referring tov Fig. 1, a frame 20, adapted to be attached to the housing (not shown) of an engine flywheel gear 2|, supports the field frame 22 of sectional view of the starting motor M, said frame 22 supporting an provided by the plate 23 and frame 20 respectively.. Shaft '25 has splines 28 engaging splines of a sleeve 29 connected with the driving member 30 of a one-way or overrunning clutch having rollers 3| through which torque is transmitted in one direction by the driving member 30 to a driven member 32 connected withfa' pinion 33 adapted to mesh with the gear 2| but normally out of engagement therewith. A collar 34 made of two parts welded together is slidable on the sleeve 28 and is retained by a split-wire snap ring 35. A spring 36 is retained under initial compression between the collar and the clutch. For further details of the starter drive, reference is made to Critchfleld Patent 2,211,053.

Frame 20 supports a pivot screw 40 for the hub lever 4| efiects movement of the pinion 33 toward.

the gear 2|. Lever 4| has a slot 44 for receiving a pin 45 extending across the arms 46 of a U-shaped link 41, said arms extending through slots 48 in a plate 49 which retains the yoke of the link. Plate 49 is attached to the armature of a solenoid unit 50 which will now be described.

Armature 5| is guided by a non-magnetizable metal tube 52 which surrounds a core 53 and which is surrounded by a magnet coil 54 of relative coarse wire and a magnet coil 55 of relatively fine wire which are surrounded by an inner shell 56 abutting plates 51 and 58 abutting plates59 and 68 respectively, the latter having a flange 6| surrounding the tube 52.

Tube 52, plate 58, insulating washers'62 and 63 and metal washer 64 are assembled to provide a spool on which the coils 54 and 55 are wound.

Core 53 and plates 51 and 59 are united by projection' welding.

Link 41, plate 49 and armature 5| are united by forcing the plate 49 into a counterbored recess 5l'a of the armature after the link arms 46 have been passed through the holes 48 in the plate. Recess 5|b of the armature provides for limited swinging movement of the link 41.

The inner shell 56 and its enclosing outer shell 66 are made by cylindrically forming sheet metal pieces. The joints or seams are not united. The joint of shell 56 and the joint of shell 66 are at the top and bottom, respectively, in Fig. 2. While these shells are squeezed together suiliciently to obtain the required inside diameters thereof, a bracket 61 is spot-welded to the outer shell. Bracket 61 has flanges 61f curved to fit the motor field frame 22 and these flanges provide four longitudinally extending slots 68 for receiving screws 69 for attaching the bracket to the field frame in the position required as will be explained later.

To the plate 60 there is assembled a felt oil impregnated seal ring 18 and a ring retainer 18a. Ring engages the armature 5| to exclude dirt and moisture.

The winding assembly (parts 52, 58, 62, 63, 64, 54 and 55), the core assembly (parts 53, 51, 59), and the plate 68 are assembled within the shell assembly (parts 56, 66, 61) and the edges of shell 66 are formed at 66a against the plates 59 and 68 to retain the parts in assembly. 7

Screws 1|a (Fig. 3) attach a bracket 1| to the plate 51. Bracket 1| insulatingly supports a terminal screw 12 to which one end each of coils 54 and 55 are connected; and terminal 12 is connected by a push button switch 5 (Fig. 1) with the non-grounded terminal of the storage battery B. Bracket 1| insulatingly supports screws 13 and 14 the heads of which provide stationary switch contacts and 16 respectively which are located so as to be bridged by a metal disc 11 (Figs. 2 and 5) which surrounds a rod 19 and is located between two non-conducting washers 11a and 18 supported by the rod 19. Washer 11a has notches 11b which receive projection 11c ofdisc 11 (Figs. 5 and 5A). Rod 19 is guided for longitudinal movement by the core 53. A- sprin re- ,tainer cup 80 supported by bracket 1|, receives a 4 spring 8|' which surrounds the left end of rod 19 and which bears against a cupped c-washer 82 received by a groove in rod 19 (Fig. 2A) and which retains the washer 82. A second cupped C-washer 83 is received by a groove 84 in rod 16 and is engaged by a spring 85, which retains the washer 83 and which bears against a washer 86 which bears against the washer 11a and urges it against the disc 11 and the latter against the washer 82. Spring 8| urges the contact disc 11 away from the contacts 15 and 16 and the washer 83 against the plate 51.

Terminal screw 13 is connected with the nongrounded terminal of battery B (Fig. 1) and the screw 14 with the insulated terminal T of the starting motor M whose other terminal is grounded. Screw 141s connected with the end of the coil 54 not connected with the terminal screw 12. The end of coil 55 not connected with the screw 12 is grounded. A cover 90 which is attached by a screw 9| to the bracket 1| has'holes for receiving the screws 13, 14 and the retainer 80.

To start the engine. the push button switch S is closed to connect both coils 54, 55 with thebattery B. The armature 5| moves left to cause the pinion 33 to move right (Fig. 1) into mesh with the gear 2| and to cause the rod 19 to move left to act through spring to press the disc 11 against the contacts 15, 1-6 whereupon the starting motor M receives current from the battery B and the coil 54 is short circuited. The coil 55 is operative to maintain the armature 5 in its leftmost position. The starting motor M cranks the engine to render it Self-operative. When the engine is self-operative, the switch S is released and spring 4 Is moves the lever 4| clockwise and starter drive to the left and against a stop sleeve 25a on shaft 25 thereby demeshing the pinion 33.

In case the ends of the pinion teeth abut the ends of the flywheel gear teeth, the solenoid armature 5| will compress the spring 36 and move the contact disc 11 into engagement with the contacts 1516. The motor turns the pinion 3.3 into meshing registration with the gear 2| whereupon the spring 36. is released quickly to move the pinion 33 into driving engagement with the gear. When the pinion is in gear abutting position 33' (Fig. 1) lever 4| will be in position 4| represented by dot-dash lines. and link 46 will be in position 46' and the right end of armature 5| will be at 5|. Therefore when. the armature 5| begins its compression of spring 36 by movement to'the left of position 5| the force opposing magnetic pull will be axial with respect to the armature 5| and the frictional resistance between the armature and its guide 52 will be practically negligible.

Therefore when the gap between the armature 5| and the core 53 is relatively wide, the magnetic force is practically unopposed by friction between the armature and its guide. As the armature 5| moves to the left of position 5| the air gap decreases and magnetic pull increases at a rate faster than the rate of increase of opposing forces clue to deflection of springs 36 and Ms and friction between the armature and its guide. By the use of a construction which results in minimum ri ional resistance between the armature and its ui e when the pinion begins abutting the wheel gear. the coils 5.4 and 55 can be made smaller than required if frictional resistance under the same condition were substantial. A reduction in ampere turns of these coils results in reduction in mechanical dimension and therefore reduction in cost of manufacture.

Asdescribed in Patent 2,302,687, the slot 44 in Ms will be unable to move the pinion 33 out of mesh with the gear 2| due to friction between these parts which could occur in case the motor is unable to rotate the engine gear after the pinion has been fully meshed therewith.

Due to slight variations in manufacture of engines, the relation of the flywheel gear to that surface of the flywheel housing to which the frame is attached, is not exactly uniform. In order that the pinion 33 can be fully meshed with the gear 2| without touching the washer b which abuts a surface of the frame 20, it is necessary to provide for adjustment of the distance through which the pinion is moved from demeshed to fully meshed position by the solenoid armature 5|. Since left movement of the armature 5| is stopped by additional compression of springs 85 and 8|, the distance through which the armature 5| and hence the pinion 33 moves is determined by the location of the solenoid bracket 61 relative to the motor field frame 22. i

To make the adjustment, the screws 69 are 100sened and the bracket 81 and the solenoidparts supported thereby are moved along the frame to the required position; and the bracket 61 is secured in the desired position by tightening screws '69. This adjustment does not change the normal position of the pinion 33 which clears the gear 2| sufficiently to allow for slight variations in relation of the gear 2| to the flywheel housing; and this adjustment does not change the established relation of collar 34, lever 4|, link 41 and solenoid armature 5| which is necessary to the transmission of force by the armature 5| axially to the link 41 at the outset of compression of spring 36 in the event of gear tooth abutment.

In place of the seal ring 10, a flexible rubber boot I00 (Fig. '7) can be used. The boot I00 has a peripheral bead |0| which fits snugly around the flange 0| of plate 60. The flange BI is deformed to provide projections I02 (Fig. 10) which retain the bead. The central portion I03 of the boot has oblong holes I04 which receive the sides 46' of the yoke-shaped link 41' when it, together with the boot, are assembled with the armature 5| by the plate 49. The sides 46 have lugs I05 I which engage the portion I03 .of the boot when the armature 5| moves to the position shown in Fig. 8 to shift the pinion and close the solenoid switch. The boot is compressed by the lugs |05 so that the bead |0| is pressed against the plate to provide a greater effective seal area as the armature 5| moves further into the solenoid housing. The lugs I05 limit relative movement be tween the boot and the sides 46 of link 41 so that wear of the boot is minimized.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. Engine starting apparatus comprising anv electric motor having a shaft, a pinion connected with the shaft and movable axially into mesh with a gear of the engine to be started, a pitotally supported lever, a spring for transmitting to the pinion the motion of the lever which effects gear engaging movement of the pinion, a main switch for connecting the motor with the current source, means for effecting saidmotion of the lever and for closing said switch, said means comiii) prising a solenoid having magnet windings and a linearly movable armature, a device for transinitting motion of the armature to the switch, a for connecting the armature with the lever, said armature operating, when said windings are energized, to move the pinion into mesh with the engine gear and to close the switch and operating, in the event of abutment of the pinion teeth with the gear teeth, to deflect said spring I while moving to close the main switch, a spring operating through the lever to retract the pinion from the gear, and a stop limiting the pinionretractive movement of the lever to a position such that the pinion clears the gear and such that, in the event of tooth abutment, the link will be axially aligned with the solenoid armature when deflection of the first spring begins.

2. Engine starting apparatus comprising an electric motor having a field frame and a shaft, a pinion splinedly connected with the motor shaft and movable axially into mesh with a gear of the engine to be started, a solenoid for shifting the pinion and for connecting the motor with a current source and comprising an armature and an assembly which includes magnet windings, a switch having a movable contact and fixed contacts engaged thereby, a device which transmits movement of the armature to the movable contact to cause it to engage the fixed contacts, a spring which resists movement of the armature to close the switch and which by its deflection limits the movement .of the armature in the switch closing direction, and a housing, a lever and a spring operable, when the windings are energized, to transmit motion from the solenoid armature to the pinion to shift the latter into mesh with the engine, said second spring yielding in the event of gear tooth abutment, to allow the solenoid armature to close the switch, a spring operating through the lever to retract the pinion,

7 to vary the amount of travel of the pinion when shifted by the armature.

3. Engine starting apparatus comprising an electric motor having a field frame and a shaft, a pinion splinedly connected with the shaft and movable into mesh with a gear of the engine to be started, a solenoid comprising an armature and an assembly which includes a housing into which a portion of the armature extends, said housing providing a support for axial movement of the armature, and which includes solenoid windings and a motor control switch actuated by the solenoid, means connecting the armature with the pinion, means for securing the solenoid housing to'the motor frame and. providing for adjustment of said housing therealong, and a cup-shaped, flexible rubber boot for enclosing the portion of the armature exterior to the housing and having its central portion connected with the armature and its peripheral portion connected with the housing, said boot permitting adjustment of the solenoid housing while the location of the armature remains unchanged. 7

JOHN E. ANTONIDIS.

No references cited. 

